Slovenia's Public Administration Minister Boris Koprivnikar on Thursday described the move as "surprising and unique." He says Slovenia's spies are required by law to ensure the basic functioning of the agency to protect national security.

Local media say the strike started Wednesday with employees of the Slovene Security and Intelligence Agency, or SOVA, complaining they are understaffed and not paid enough.

No other details about the strike, including how many employees were affected, were immediately known.